GRANITE · GRAvitational waves from Neutron stars: Investigating Transient Emission
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2016-10-01 → 2018-09-30
- EU contribution
- €195,455
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
GRAvitational waves from Neutron stars: Investigating Transient Emission
The GRANITE project aimed at detecting transient gravitational waves (GWs) from spinning neutron stars. Such signals would provide novel insights about nuclear matter at extreme densities, the mechanisms of pulsar glitches, the formation and population properties of neutron stars in our Galaxy and beyond, and gravity itself. When the proposal was submitted, humanity had not yet ever detected GWs. But in 2015, a hundred years after Einstein predicted these new cosmic messengers, the LIGO and Virgo collaborations detected the first GWs from merging black holes. Several more GW observations, including one collision of neutron stars, have since been made, and the fellow has contributed to all these discoveries as a member of the LIGO Collaboration. A completely new observational window on the Universe has indeed been opened, though on a different class of sources than initially targeted in this project. Still, I have dedicated most of my research during this project to searching for GWs from individual neutron stars. The prime targets originally were glitching pulsars in our Galactic neighbourhood. However, with the fortunate detection of the binary neutron star merger GW170817, priorities were shifted towards this fascinating new source. Hence, this project has indeed delivered the promised first model-based search for medium-duration GW transients from neutron stars, but instead of targeting nearby glitching pulsars, I have led an international team of LIGO and Virgo scientists in a search for transient post-merger emission from a putative neutron star remnant of GW170817. As a third aspect of this MSCA fellowship, method development has continued towards the initial goal of searching for transient GWs from glitching pulsars, improving the computational efficiency of the available analysis methods and preparing post-glitch searches targeted at the nearby Crab and Vela pulsars.
Data: CORDIS, © European Union
Project objective
In this research project we will perform the first search for a promising new type of gravitational-wave signal from neutron stars: medium-duration transients (MDTs). We will use data of unprecedented sensitivity from the new detectors Advanced LIGO and Advanced Virgo. A successful detection will provide a novel test of gravity and unique insights into the structure of neutron stars.Gravitational waves (GWs) were predicted by Einstein a century ago, but are extremely hard to detect. Their first direct observation will herald the start of a new era in astronomy but requires specialised searches to extract the full astrophysical information about each source. Much effort already goes into the search for continuous waves (CWs) emitted by rotating neutron stars (NSs) with non-axisymmetric deformations, which should be observable over many years. Only very weak CWs are expected, but NSs can also emit relatively strong transient GWs on much shorter timescales. In this fellowship we will develop and implement the first practical search for signals spanning these extremes, bridging the gap between continuous and transient phenomena.Based on an explicit CW-like signal model, limited in duration, and on a Bayesian model selection approach, we will first construct an optimal detection method for medium-duration transient (MDT) signals taking into account astrophysical priors on transient GW emission from rotating NSs. Second, we will use synergies with established CW data-analysis methods to guarantee an efficient implementation and build on previous experience to account for complex detector noise properties. We will then apply these newly-developed methods to the best advanced-detector data available. This novel CW-based transient search will be the first to provide the ability to detect NSs as MDT sources, to estimate their astrophysical parameters with high precision, and to infer their internal properties which are inaccessible through other observational methods.
Original text from CORDIS.
Participants
- UNIVERSITY OF GLASGOW · GlasgowCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union